Vibrational relaxation of HCN(002)

Journal Article · Tue Mar 15 04:00:00 EST 1983 · J. Chem. Phys.; (United States)

DOI:https://doi.org/10.1063/1.445111· OSTI ID:5502775

Hastings, P W; Osborn, M K; Sadowski, C M; Smith, I W.M.

Tuned output from an optical parametric oscillator has been used to excite HCN to its (002) level for measurements of vibrational energy transfer. By observing time-resolved (002,001) fluorescence in the presence of different collision partners, the following rate constants (k/sub 002//cm/sup 3/ molecule/sup -1/ s/sup -1/) were obtained for relaxation of HCN(002) at 298 +- 4 K: k/sub HCN/ = (6.8 +- 0.4) x 10/sup -12/; k/sub He/ = (5.6 +- 0.25) x 10/sup -15/; k/sub Ne/ = (3.8 +- 0.16) x 10/sup -15/; k/sub Ar/ = (3.0 +- 0.4) x 10/sup -15/; k/sub Kr/ = (3.25 +- 0.12) x 10/sup -15/; k/sub 02/ = (1.39 +- 0.08) x 10/sup -14/; k/sub N2/ = (2.6 +- 0.15) x 10/sup -14/; k/sub CO/ = (6.8 +- 0.4) x 10/sup -14/. These results are compared with the rate constants (k/sub 001/) obtained for relaxation of HCN(001) and the mechanisms for relaxation are discussed. With noble gases as collision partners, the ratios (k/sub 002//k/sub 001/) are less than one. Comparison of these ratios with predictions of the ''breathing sphere'' theory indicates that relaxation of HCN(00v/sub 3/ = 1,2) occurs via transfer to HCN(12/sup 0/ )v/sub 3/-1)), the lower rate for v/sub 3/ = 2 being due to the increased energy gap between initial and final states.

• Research Organization: Department of Physical Chemistry, University Chemical Laboratories, Lensfield Road, CambridgeCB2 1EP, England
• OSTI ID: 5502775
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 78:6; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

640304* -- Atomic
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
ARGON
ATOM COLLISIONS
ATOM-MOLECULE COLLISIONS
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CHALCOGENIDES
COLLISIONS
CYANIDES
ELEMENTS
ENERGY LEVELS
ENERGY TRANSFER
EXCITED STATES
FLUIDS
FLUORESCENCE
GASES
HELIUM
HYDROCYANIC ACID
HYDROGEN COMPOUNDS
INORGANIC ACIDS
KRYPTON
LUMINESCENCE
MOLECULE COLLISIONS
MOLECULE-MOLECULE COLLISIONS
NEON
NITROGEN
NONMETALS
OXIDES
OXYGEN COMPOUNDS
RARE GASES
RELAXATION
VIBRATIONAL STATES